1. Field of the Invention
This invention relates to a crusher comprising a series of cutter units mounted on a pair of shafts arranged parallel to each other so as to rotate in the opposite directions to each other.
2. Description of the Prior Art
In the conventional solid waste crushers, as diagrammatically illustrated in FIG. 1, a pair of parallel shafts 13, 13' arranged to rotate in the opposite directions to each other are provided in a casing 12 having a hopper-like feed port 11, and cutter blades 14, 14' are mounted on the respective shafts such that said cutter blades 14, 14' contact each other partly at their sides so as to perform crushing of the waste material by shearing force.
In order to facilitate biting of the material to be crushed, each of the cutter blades 14, 14' is provided with radially extending protuberant portions 15, 15' along its outer periphery. These protuberant appendices, however, complicate the configuration of the cutter units and also could vary the shearing angle at which every associated cutter blades meet each other to make the horsepower requirement per unit time unstable during rotation, resulting in increased energy consumption and reduced power.
Further, in this type of crusher, there are usually used disc-shaped members with a radius which is the same as the filler blocks between the cutter blades on each shaft, so that if a break-down degree adjusting screen is provided beneath these members, such screen would soon become clogged and thus invite a reduction of discharging performance and an added difficulty in recycling the insufficiently worked material back to the cutting system, resulting in an excessively lowered disposal capacity. Moreover, the insufficiently crushed material would stagnate below the cutter blades to act as a brake against the rotating elements, causing wasteful consumption of power and abnormal evolution of heat. Another serious disadvantage of conventional crushers is that it is necessary to disassemble the main shaft for replacing worn-out cutter blades. Such disassembling and re-assembling of the shaft is very troublesome and time-consuming.